Cutter head



July 31, 192s. 1,678,820

L. T. MEDHOLDT CUTTER HEAD July 31, 1928. 1,678,820

L. T. MEDHOLDT CUTTER HEAD Filed Maron 2o, v1925 2 lshams-sheet 2Patented July 3l, 1928. i MIIB STATES PATENT OFFICE.

LOUIS T. MEDHOLDT, OF ROCKFORD, ILLINOIS, ASSIGNOR TO MATTISON MACHINEWORKS, OF EOCKFOB-D, ILLINOIS, A. CORPORATION OF ILLINOIS.

CUTTER HEAD.

Application filed March 20, 1925. Serial No. 16,902.

rlhe invention relates to cutter heads of stantially nearer the axis ofthe cutter than thetype used in moulders and other wood with the priorconstruction above referred working machines, and the object of theinto, with the result that it is possible to opvention, generallystated, is te provide a crate the head at much higher speeds with- 5head of improved construction whereby the out subjecting the same toundue strain due 60 cutter blades may be more efiectually mountto theaction of centrifugal force. ed in the head than heretofore. In theaccompanying drawings I have A common form of cutter head at presentshown my invention as applied to a cutter in use in the wood working artis a subhead which is one instance comprises a holl stantiallyrectangular head providing upon low body having four side walls formedin- 55 its outer sides clamping faces for the cutter tegral withopposite end walls and in anblades, the latter being secured upon saidother instance comprises a hollow body havfaces by means of bolts havingflat heads ing two opposed side walls formed integral entered inundercut or T-slots formed in the with opposite end walls and two sidewalls l5 faces of the head. Considerable difficulty formed separatelyfrom the end walls so 70 has been experienced with heads as thus conasto be removable at will, the separable structed because the blades aresubjected to walls being securely held in interengaginfr severe strainsand being unsupported by the relation with the end walls. In a copendinrbody or head are frequently broken loose application Serial No. 11,059,filed February 20 from the head, the clamping bolts giving 24, 1925, Ihave shown a cutter head cori- 75 away under the strain. struction inwhich four side walls are formed Various elforts have, in the past, beenseparately from the end walls, but clamped made to remedy thisdifficulty, but such eftogether into a rigid unit. Other embodifortshave not, so far as I am aware, met ments of the invention with variouschanges 25 with success. My invention therefore has in construction andarrangement may, it is 80 for its especial aim the solution of thediliicontemplated, be produced by those skilled culty in a thoroughlypractical manner. in the art without departing from the spirit Thus itis desirable not only that a. rigid and scope of the invention asexpressed inV support or backing be provided in the body the appendedclaims.

of the head for each blade, but it is desirable Figure 1 of the drawingsis a fragmentary 85 that the strains incident to clamping each sideelevational view of a cutter liead havblade in position in the head beconfined to ing four side walls integral with opposite the side wall ofthe head to which it is seend walls.

cured so as to avoid distorting the head. I Fig. 2 is a longitudinalsectional view 35 attain this result by my invention which through thesame. no

consists generally in making the head in Fig. 3 is a transversesectional view taken the form of a hollow body having interiorapproximately in the plane of line 3-3 of dimensions transversely of thebody substan- Fig. 1. l

tially greater than the diameter of the sup- Fig. 4c is a similar viewbut taken in the porting spindle passing through the body; plane of line4-4 of Fig. 1. 95

providing slots 'in the body to receive the Fig. 5 is a fragmentary sideelevational blades with their inner ends lying against view of a cutterhead having'two side walls the inner faces of the side walls of thebody; formed integral with the end wall and two and rigidly securing theblades upon said side walls formed separately therefrom.

inner faces by means of clamping bolts en- Fig. 6 is a transversesectional view taken 100 tered through the blades and the side wallsapproximately in the plane of line 6-6 of with which they respectivelyengage. By Fig. 5.

this arrangement, each of the blades is lirm- Fig. 7 is a similar viewbut showing the ly supported or backed adjacent its cutting separablewall sections removed.

edge by the rigid side walls, and the strains Fig. 8 is a detachedelevational view of a 105 incident to clamping each blade in positionpart of the means for clamping the head are confined to the side wall towhich it is upon the spindle.

clamped. A further advantage is that the Referring first to the formshown in Figs. inner ends of the blades and the major por- 1 to 4l, thecutter head comprises a hollow tion of the clamping means are disposedsubbody having opposite end walls 10 and 11 110 clamping faces 21.

apertured centrally thereof to receive the supporting spindle 12 and theclamping means whereby the head is secured to the spindle. Inasmuch asthisclamping means forms, per sano part of this invention, it may bedescribed briefly as comprising a sleeve 13 (Fig. 8) having a conicalhead 14. at one end adapted to engage with a tapered bearing surface 15in the end wall 11 of the head. The sleeve is slotted throughout itslength so as to be contractible and at the end opposite the head 14- itis screw-threaded as indicated at 16 to receive a clamping nut 17between which and the end wall 10 is interposed a split conical ring 18bearing against a tapered surface 19 formed in. the wall 10 of the head.`rllightening the nut 17 serves to .clamp the head centrally upon thespindle 12.

y l have herein shown the body of the head having an outer surfacegenerally cylindrical in form. The end walls are connected by four sidewalls 20, 20H, 20h and 20. Vxhile the outer sides of these walls arecirr cular or arcuate in form the inner sides are preferably shaped toprovide flat inner These in the present instance form a substantiallyrectangular chamber the transverse dimensions of which are substantiallygreater than the diameter of the spindle 12, thus providing a spacebetween the spindle and each of the faces 21 for accommodating thecutting blades and their securing means.

Leading' from the interior of the head outwardly through the body at onelongitudinal edge of each side wall is an approximately tangential slot22 having one wall formed as a continuation of the clamping face 21, andupon each clamping` face 21 may be secured a cutting blade 23 the outerend portion of which projects through a slot 22 sliglrtly beyond theouter periphery of the head.

The means for clamping the connecting blades 23 upon their clampingfaces 21 preferably comprises, in each case, a bolt 24.- entered throughan elongated opening or .slot 25 in the side wall. The blades have theirinner ends provided with longitudinal slots 26 for receiving the bolts24, and preferably the bolt is passed from the interior of the headoutwardly through the side wall, the outer end being provided with a nut27 which together with a washer 28 is countersunk Iin an elongatedrecess 29 formed in the outer face of the side wall. The head 30 of thebolt is made relatively flat and the sleeve 13 may be cut away upon four.sides as shown clearly at 31 (Fig. 4') to provide increased space forthe head 30 of the bolt.

It will be seen that by this construction a firm support or vbacking inthe body of the head is provided for each blade, near its cutting edge,and that the blade is clamped in position in such a way that theclamping strains are conned entirely to the side wall to which it issecured, thus avoiding any possible distortion of the head. l

Referring now to Figs. 5 and 6, the construction is generally similar tothat shown in 1 to l except that in this instance only the side walls 2Oand 2OJ are formed integral with the end walls, the side walls 20a and20C being made in ,separate approximately segmental sectionsinterengaging at opposite ends with the end walls and secured inposition by means of longitudinal clamping bolts 32. In order that theseremovable wall portions may be securely held in position their oppositeends are shaped to engage in grooves 34 having inclined faces 35arranged to prevent radial outward movement of these wall sections. Thelatter are slid edgewise into place and securely clamped againstmovement in the grooves by means of the bolts 32 which are enteredthrough elongated grooves 35 in the inner faces of the wall sections andnear one edge thereof. The opposite ends of the bolts lpass throughsuitable apertures 37 in the end wallsV 10 and-.11.

lt frequently'is desirable to employ in the cutter head two blades only.It will be observed in this connection vthat the construction shown inFigs. 5V and 6 lends itself readily to the use of twoblades, it beingonly necessary to remove the separable sections 20 and 20", the clampingof each blade upon its clamping face being entirely independent ofadjacent side walls.

I claim as my invention: l

1. A high speed cutter head comprising, in combination, a hollow bodyhaving rigid ond and side walls and adapted to be mounted upon asupporting' spindle, the interior dimensions of said body beingsubstantially greater than the diameter of the spindle,

cutting blades having their inner ends lying within the body `and theirouter ends projecting therefrom, there through, and radial clampingbolts entered perpendicularly through said blades and the side walls ofthe body for clamping the being openings inl the body to permit saidblades to pass therelll) blades rigidly upon the inner faces of said fside walls, the heads of said bolts being d-isposed between the spindleand the blades upon the inner faces of the body so that tjhe spindlelimits inward movement of the olt. i

2. A cutter head of the character described comprising a hollow bodyhaving end walls centrally apertured to receive the supporting spindle,and a plurality of side walls rigid with the end walls, the inner facesof said side walls extending to a point close to the adjacent blade andproviding clamping surfaces for a pl rality of cutter blades, said bodyhaving longitudinally extending ifio lili) slots therein one wall ofeach of which is flush with the inner face of a side wall, bladesentered through said slots and lying against said inner faces of theside Walls, and bolts entered radially through the side walls forclamping the blades in position upon said clamping surfaces.

l 3. A high speed cutter head comprising a hollow body, bladesprojecting outwardly through the body, the body having end walls andside walls with inner faces against.

which the inner portions of the blades may be secured, and means passingthrough the side walls of the body for clamping the blades against sailclamping surfaces, al ternate side walls of the body being formedintegral with the end walls and the remaining side walls being formedseparately therefrom and Vdetachably secured thereto.

ll. A high speed cutter head of the character described comprising, incombination, a hollow body having a pair of end walls and a pair of sidewalls formed integral with the end walls at opposite sides of the head,each of said side walls providing an inner face upon which a knife blademay be secured, said body also having a second pair of side walls formedseparately from said end walls and having bevelled ends adapted tointerengage with correspondingly bevelled surfaces on the adjacent sidesof the end walls, said second pair of side walls also providing clampingsurfaces for knife blades, and means for detachably securing said.second pair of side walls between said end walls.

5. A cutter head of the character. described comprising a hollow bodyhaving a pair of end walls and a pair of side walls formed integral withthe end walls at opposite sides ofthe head, each of said side wallsroviding an inner face upon which a cutting blade may be secured and anopening therein through which may extend a bolt for clamping the bladeupon said inner face with the blade supported by the side wall at apoint adjacent its cutting edge, said body also having a second pair ofside walls formed separately from said end walls but interengagingtherewith and each providing a clamping face for a cutting blade, andmeans for detaohably securing said second air of side wallsbetween saidend walls.

6. A cutter head comprising a hollow body generally cylindrical in formand pro viding a substantially rectangular chamber therein, the walls ofwhich are disposed approximately tangentially of the head, and clampingbolts entered radially through the side walls of said body and adaptedto clamp cutting blades upon the inner faces of said walls, there beingnarrow slots in the body through which said blades may project beyondthe outer periphery of the body.

7. A cutter head comprising a hollow body having rigid end and sidewalls and adapted to be mounted on a supporting spindle, cutting bladeshaving their inner ends lying within the body and theirouter endsprojecting therefrom, there being openings in the body to permit theblades to pass therethrough, and clamping bolts entered through saidblades and the side walls of the body for clamping the blades rigidly tosaid side walls, said bolts having integral heads disposed between thespindle and the blades and being arranged for limited movement inwardlyof the body when t-he cutter head is mounted upon the spindle.

In testimony whereof, I have hereunto affixed my signature. l

LOUIS T. MEDHOLDT.

